In its heyday, the coal-fired plant continuously produced 370 megawatts of electricity, with each megawatt able to power a thousand households. But its last coal-fired units were shut down a few years ago. Piles of coal are long gone. Across the compound here in the center of this mid-Atlantic state, three noisy turbines churn at a new natural gas-fired plant that produces 620 megawatts. The Buck Combined Cycle power station stands at the edge of the Yadkin River—and amid a wave of change in the energy industry. Both plants are owned by Duke Energy, a company with holdings in the United States and Latin America.
In 2011, Duke Energy shuttered its coal-fired power plant, at rear, and opened a new plant that runs on natural gas. Its water-treatment facility appears, in foreground, in Rowan County, North Carolina.
Growing demand
Like other U.S. energy firms, it is responding to growing demand for cleaner energy and tighter restrictions on carbon emissions. American firms are being compelled to reduce their dependence on coal in favor of much cleaner fuel sources. Bill Wilson, senior engineer at the Buck Combined Station, said Duke has retired about half of its coal-fired facilities in recent years and replaced them with natural gas facilities like this. "Due to the current price of natural gas, it is much cheaper,” he explained. “So on a megawatt basis, it is cheaper to run natural gas than coal." It costs between $15.30 and $17.30 per megawatt hour (MWh) for natural gas, while coal costs about $28 per MWh, Duke Energy spokeswoman Tammie McGee said. "So, in today’s markets, our natural gas generation does provide lower costs and savings to our customers," she added. Duke Energy plans to phase out most of its U.S. coal plants in next few decades.
American Electric Power converted its Clinch River Plant in Virginia from coal to natural gas, idling the conveyor belt that once carried coal up into the plant.
Switching over
The shift also is evident in other energy companies across the country. For decades, coal was the main fuel source for generating power in the United States. Last year, natural gas matched it, with each producing a third of the nation’s electricity, according to U.S. Energy Information Administration figures. The other third came from hydropower, nuclear and renewable energy sources. The administration had predicted that natural gas would overtake coal as the country's biggest source of electricity this year, though this week it posted a story headlined, "Coal may surpass natural gas as most common electricity generation fuel this winter."
Generating changes
About 200 miles northwest of Salisbury, in mountainous Russell County, Virginia, a couple of trucks and a bulldozer in July removed the last few tons of black coal from a field outside the Clinch River Coal Plant. The plant’s three coal-fired units once produced up to 705 megawatts of electricity. But early this year, plant owner American Electric Power converted two of the units to gas and retired the third. The new units are not only cleaner, they are more efficient, plant manager Ricky Chaffin said. Now, the plant can produce 484 megawatts of electricity—averaging 242 megawatts per unit, up from the previous 235 each. And running it requires less labor. "You don't have to handle the coal," Chaffin said. "You don't have to move the coal from the pile to the plant.” Also, natural gas is delivered via pipeline. “We have got a lot less equipment,” Chaffin added. “So it's a whole lot less manpower required to run a gas plant."
Workers are installing solar panels at a Duke Energy solar farm in Union County, North Carolina. The mid-Atlantic state ranks second, nationally, in solar capacity.
